The invention relates to improvements in devices for coupling dentures to natural teeth, and more particularly to improvements in devices for separably coupling bridges, prostheses and other types of dentures to artificial or non-artificial crowns of natural teeth.
German Utility Model No. 85 17 420 of Janzen discloses a coupling device wherein a sleeve-like male detent member which is attached to the denture can be separably inserted into a socket on a crown by means of a screw which can be driven into the detent member. The latter is slotted and is made of a resilient metallic material which is subject to extensive wear. Moreover, it is not possible to correct the orientation of an improperly oriented detent member. Still further, the cost of the coupling device is very high because the socket must be soldered to the crown. The cost of replacing a damaged or broken part of the coupling device is also very high.
Coupling devices which are similar to the coupling device of Janzen are disclosed in Swiss Pat. No. 528 260 to Guglielmetti and in German Offenlegungsschrift No. 33 39 084 of Veit.
German Offenlegungsschrift No. 35 15 819 of Sulc discloses a coupling device wherein the male detent member is releasably held in the socket on a crown by snap action.
French Pat. No. 1,493,268 to Cleveland discloses a male detent member which is slotted and can be expanded by the conical head of a screw so that it bears against the internal surface of a female detent member. The male or female detent member is anchored in the root of a natural tooth.
U.S. Pat. No. 2,694,858 to Cluytens discloses a mounting for artificial teeth wherein the socket on a tooth crown receives a male detent member which is held therein by a screw. An elastic washer surrounds the shank of the screw and is caused to expand against that end face of the socket which is adjacent the head of the screw.
Commonly owned copending patent application Ser. No. 07/214, 756 filed May 16, 1988 discloses a method of providing a tooth crown with a channeled female detent member. This application does not disclose any means for expanding the male detent member which extends into the channel of the female detent member when the crown supports a prosthesis.